Bio-degradable cup and method for making the same

ABSTRACT

A bio-degradable cup includes a foam cup and a paper cup which is securely received in the foam cup. The paper cup includes a bio-degradable film coated to an inside thereof. The paper cup is formed by cutting a paperboard and folded to be the paper cup. The foam cup is made by preparing a foam board made by bio-degradable plastic which is treated by way of super-critical carbon dioxide extrusion, the foam board is cut into pieces and each piece is made to be the foam cup. The foam cup is applied with a heat treatment to obtain a sticky inner surface to which the paper cup is securely connected. A lip is formed around an outer top edge of the foam cup.

FIELD OF THE INVENTION

The present invention relates to a bio-degradable cup and a method for making the same.

BACKGROUND OF THE INVENTION

A conventional biodegradable cup generally includes an inner cup which is used to receive food and does not deform, and a paper outer paper cup in which the inner cup is received. The inner cup is made by bio-degradable material and is made by way of super-critical carbon dioxide extrusion. The paper outer cup includes printed material on outside thereof.

However, the inner cup and the paper outer cup are simply engaged with each other so that the inner cup may shift relative to the paper outer cup. The inner cup may also become soft when hot food is received in the inner cup and this results health concerns.

The present invention intends to provide a bio-degradable cup which includes a paper cup connected to inside of a foam cup which is made by bio-degradable material and the paper cup is securely bounded to inside of the foam cup. A bio-degradable film is coated to the inside of the paper cup.

SUMMARY OF THE INVENTION

The present invention relates to a bio-degradable cup which comprises a paper cup with a bio-degradable film coated to an inside thereof and a foam cup in which the paper cup is received. The foam cup is made by microfoam which is made by way of super-critical carbon dioxide extrusion. A lip is connected to a top edge of the foam cup and a foam pad is connected to an underside of the foam cup.

The present invention further relates to a method for making a bio-degradable cup, and the method comprises the following steps:

a step of preparing a paperboard with bio-degradable film coated on at least inner or outer surface thereof, the paperboard then being cut and folded to be a paper cup;

a step of preparing a foam board made by biodegradable plastic which is treated by way of super-critical carbon dioxide extrusion, the foam board being cut into pieces and each piece being made to be a foam cup;

a step of applying a heat treatment to an inside of the foam cup to obtain a sticky inner surface of the foam cup and the paper cup being securely connected to the sticky inner surface of the foam cup, and

a step of making a lip around an outer top edge of the foam cup.

The primary object of the present invention is to provide a cup suitable for receiving food and can be bio-degradable.

Another object of the present invention is to provide a method for making the bio-degradable cup.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows steps of the method for making the bio-degradable cup of the present invention;

FIG. 2 shows a foam pad is to be connected to an underside of the foam cup;

FIG. 3 is a cross sectional view to show the biodegradable cup of the present invention;

FIG. 4 shows that the foam cup is made by the foam piece;

FIG. 5 shows another embodiment of the bio-degradable cup of the present invention, wherein the lip is separately made and then connected to the foam cup, and

FIG. 6 shows a further embodiment of the bio-degradable cup of the present invention, wherein the top edge of the foam cup is located at ⅓ height from the bottom of the paper cup.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the method for making the bio-degradable cup of the present invention comprises a step of preparing a paperboard with bio-degradable film 11 coated on at least inner or outer surface thereof, the paperboard then being cut, folded and heat-pressed to be a paper cup 10. The bio-degradable film 11 is made by Plolylactic Acid (PLA), Bio-Polymers, bio-degradable plastic or any plastic material meets requirements ISO14855 and suitable to be composted.

A step of preparing a foam board 200 made by bio-degradable plastic or non-bio-degradable plastic which is treated by way of super-critical carbon dioxide extrusion. The foam board 200 is a microfoam and is applied with a printing process which can be water relief printing, intaglio printing, lithography, screen printing or rotary screen. Desired patterns or characters can be printed to the outside of the foam board 200 and the foam board 200 is cut into pieces and each piece is made to be a foam cup 20 via necessary steps such as folding, ultra-sonic heat pressing, ultra-wave pressing, hot-air heating, or electric heat pressing. The bio-degradable plastic is one of Plolylactic Acid (PLA), Bio-Polymers, or bio-degradable plastic. The non-bio-degradable plastic is one of Polyethylene (PE), Polypropylene, or Polyethylene Terephthalate (PET).

A step of applying a heat treatment to an inside of the foam cup 20 to obtain a sticky inner surface of the foam cup 20 and the paper cup 10 securely connected to the sticky inner surface of the foam cup 20. The heat treatment can be any known ways such as ultra-sonic heating, electric heating, ultra-wave heating or hot-air heating. The temperature of the heat treatment to the inside of the foam cup 20 is about 60° C. or higher than 60° C. to make the inside of the foam cup 20 to be sticky and the paper cup 10 is inserted into the foam cup 20. A proper mold is used to securely connect the paper cup 10 to the foam cup 20. The inside of the foam cup 20 can also be applied a layer of bio-degradable Bio-polymer which is adhesive so as to securely connect the paper cup 10.

A step of making a lip 21 around an outer top edge of the foam cup 20. The lips 21 of adjacent bio-degradable cups are in contact with each other when the bio-degradable cups are piled up. As shown in FIG. 4, the lip 21 can be formed by pressing an outward portion along the top edge of each fan-shaped piece so that the outward portion 201 forms the lip 21 when the foam cup 20 is formed.

As shown in FIG. 5, the lip 21 can be made by another foam board which has different thickness from the foam board 200 to be made the foam cup 20, the lip 21 is securely connected to top edge of the foam cup 20. The paper cup 10 can be connected with the foam board 200 after or before the connection of the lip 21 and the foam cup 20.

A step of connecting a foam pad 22 to an underside of the foam cup 20 and a diameter of the foam pad 22 being the same as an outer diameter of the foam cup 20.

The bio-degradable cup of the present invention made by the method described above comprises a paper cup 10 with a biodegradable film 11 coated to an inside thereof and a foam cup 20 in which the paper cup 10 is securely received. As shown in FIG. 3, the paper cup 10 includes another lip which protrudes outward from a top edge of the paper cup 10 and then is curved inward. The another lip on the paper cup 10 is rested on the lip 21 of the foam cup 20.

As shown in FIGS. 1-5, the outward and curved lip on the paper cup 10 is rested on the lip 21 on the foam cup 20 when the bio-degradable cups are piles up. As shown in FIG. 6, the top edge of the foam cup 20 is located at about ½ to ⅓ height from the bottom of the paper cup 10. A lower edge of the foam cup 20 is in flush with a bottom of the paper cup.

The biodegradable film 11 is made by Plolylactic Acid (PLA), PHA, Bio-Polymers, bio-degradable plastic, Biomax PET, Fepol, Ecoflex, Mater-be by DuPond Company, or any plastic material suitable to be composted and meets requirements of International Standard Organization. The bio-degradable plastic is one of Plolylactic Acid (PLA), Bio-Polymers, bio-degradable plastic or Thermoplastic that is suitable to be composted. The foam material for the foam cup 20 can be Polyethylene (PE), Polypropylene (PP), or Polyethylene Terephthalate (PET).

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A method for making a bio-degradable cup, comprising: a step of preparing a paperboard with a bio-degradable film coated on at least an inner or outer surface thereof, the paperboard then being cut, folded and heat-pressed to be a paper cup; a step of preparing a foam board made by bio-degradable plastic which is treated by way of super-critical carbon dioxide extrusion, the foam board being cut into pieces and each piece being made to be a foam cup; a step of applying a heat treatment to an inside of the foam cup to obtain a sticky inner surface of the foam cup and the paper cup being securely connected to the sticky inner surface of the foam cup, and a step of making a lip around an outer top edge of the foam cup.
 2. The method as claimed in claim 1 further comprising a step of connecting a foam pad to an underside of the foam cup and a diameter of the foam pad being the same as an outer diameter of the foam cup.
 3. The method as claimed in claim 1, wherein the bio-degradable film is made by Plolylactic Acid (PLA), Bio-Polymers, bio-degradable plastic or any plastic material suitable to be composted.
 4. The method as claimed in claim 1, wherein the bio-degradable plastic is one of Plolylactic Acid (PLA), Bio-Polymers, or bio-degradable plastic.
 5. The method as claimed in claim 1, wherein the non-bio-degradable plastic is one of Polyethylene (PE), Polypropylene, or Polyethylene Terephthalate (PET).
 6. The method as claimed in claim 1, wherein the lip on the foam cup is located beneath an outward and curved lip on the top edge of the paper cup.
 7. The method as claimed in claim 1, wherein the top edge of the foam cup is located at ½ to ⅓ height from the bottom of the paper cup.
 8. A bio-degradable cup comprising: a paper cup with a bio-degradable film coated to an inside thereof; a foam cup in which the paper cup is received, the foam cup made by microfoam made by way of super-critical carbon dioxide extrusion, a lip connected to a top edge of the foam cup and a foam pad is connected to an underside of the foam cup.
 9. The method as claimed in claim 8, wherein the lip on the foam cup is located beneath an outward and curved lip on the top edge of the paper cup.
 10. The method as claimed in claim 8, wherein the top edge of the foam cup is located at ½ to ⅓ height from the bottom of the paper cup. 